1. Field
The following description relates to a super-regenerative receiver (SRR).
2. Description of Related Art
In general, a super-regenerative receiver (SRR) may be configured with much lower energy, lower power consumption, and fewer components. In addition, the SRR may be operated at a lower voltage, when compared to a homodyne or super-heterodyne receiver, and thus, may be suitable for a communication system using a low-cost and low-power receiver.
An SRR-based reception technique may be non-coherent in nature as a phase of an incoming signal may not play a role in a detection process. Hence, the SRR-based reception technique may rely on amplitude-based modulation techniques, namely, on-off keying (OOK), to transmit information, and be operated in a linear mode or a logarithmic mode based on whether an output is saturated. The OOK may be the simplest form of amplitude-shift keying (ASK) modulation in which digital data is represented as a presence or absence of a carrier wave.
In a number of wireless networking schemes, data may be shared using packets transmitted in a random access manner through a wireless channel. A receiver in such an arrangement may not be aware of a receipt time of a packet, and thus, monitoring the wireless channel and attempting to detect a packet upon arrival are necessary. The packet detection may be performed by correlating an input signal of the receiver with another signal to generate a correlation coefficient. The input signal may be cross-correlated with a pattern known to be within a header of each packet, or auto-correlated with itself, to generate the correlation coefficient. Once the correlation coefficient is generated, the correlation coefficient may be compared to a fixed threshold value to determine whether a packet has arrived. Arrival of a packet may be assumed when the correlation coefficient is greater than the fixed threshold value.
When noise results in a correlation coefficient greater than the fixed threshold value used by a receiver, the receiver may improperly indicate detection of a packet, resulting in a situation referred to as a false alarm. When a false alarm occurs, the receiver may process a signal before the detection is recognized as a false alarm, and thus, energy may be wasted due to unnecessary signal processing being performed by the receiver. Subsequent to recognition of a false alarm, a state of the receiver may be reset to an acquisition mode. When an actual packet is received before the state of the receiver is reset, or when a strength of the signal is poor when compared to the noise, the packet may not be detected by the receiver, resulting in a missed packet. Retransmission of the missed packet may be necessary, which may result in a reduction of throughput in a network as well as an unwarranted consumption of energy. Due to low power consumption in devices, such as, battery operated devices, being a major global research goal at present, there is a desire for developing receiver techniques to increase a packet detection rate while minimizing a false alarm rate of a wireless network receiver, namely, in a low signal-to-noise ratio (SNR) region. The developing of receiver techniques may have a benefit of not only reducing retransmissions and switching off unwanted signal processing, but also reducing transmission power. In consideration of a fact that power amplifiers in transmitters are inefficient in current technology, reducing transmission power may have an even higher order impact.